| 摘要 |
PURPOSE:To increase the adhesion between an electrode shaft and the main body of the electrode and eliminate occurrence of a falling off of the electrode, by inserting the electrode shaft, made of a matal having a high melting point and provided with a layer of an oxide on its surface, into a powder mixture adapted to serve as the main body of the electrode, performing a compression molding and sintering it in a reducing atmosphere. CONSTITUTION:On surfaces of an electrode shaft made of a metal having a high melting point, an oxide layer is formed, and said electrode shaft is inserted into granulated powder containing an electron emitting material and high melting point metal powder, after a compression molding, sintered in a reducing stmosphere. For instance, a tungsten bar of 0.5mm. in diameter is heated in air for 30min at 600 deg.C and a layer of low grade tungsten oxide is formed into a thickness of about 0.3mu on its surface. The granulated powder is formed by blending tungsten powder and an electron emitting material like yttrium oxide, barium carbonate or the like, molded and inserted with the above described tungsten bar, and then subjected to compression molding. Said molded body is heated to 1,000 deg.C in a reducing atmosphere to perform its presintering, followed by a sintering for an hour at 1,350- 1,500 deg.C. The sintered body is then rapidly cooled to obtain an electrode of dimensions: A=2.4mm.phi and B=2.7mm.. |
